I found time tonight to assemble the kit. I want to thank GRJ for designing the board in his usual excellent manner, and rtr12 for compiling the kit. Having color distinction problems, I really appreciated rtr12 marking the sets of resistors with their values. Saved me the problem of either asking Mrs RJR to tell me the colors, or pulling out my trusty Fluke.
Up in this thread is a picture of a board on which the author had superimposed indication of where the flat sides and white stripes go. Very helpful.
I plugged it into a Rev L Fixed circuit without calibrating, and fired up the layout. The red came on whenever I sent a signal, and the green rarely. What puzzled me is that when trains were running, both green & red would flicker periodically.
Now to read back through this thread to study calibration & operation.
As an aside, I have an occasional doubletoot problem with softkeys. I notice there was no flash before the second toot. After closing down, occurred to me that I can put it on the other TIU and see if there is crosstalk causing the 2nd TIU to also issue a signal.
GRJ & RTR12: Hope you guys produce more useful kits.
